mirror of
https://github.com/eledio-devices/thirdparty-littlefs.git
synced 2025-10-31 00:32:38 +01:00
1773 lines
44 KiB
C
1773 lines
44 KiB
C
/*
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* The little filesystem
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*
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* Copyright (c) 2017 Christopher Haster
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* Distributed under the MIT license
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*/
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#include "lfs.h"
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#include "lfs_util.h"
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#include <string.h>
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#include <stdlib.h>
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/// Block device operations ///
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static int lfs_bd_flush(lfs_t *lfs) {
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if (lfs->pcache.off != -1) {
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int err = lfs->cfg->prog(lfs->cfg, lfs->pcache.block,
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lfs->pcache.off, lfs->pcache.buffer, lfs->cfg->prog_size);
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if (err) {
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return err;
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}
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lfs->pcache.off = -1;
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}
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return 0;
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}
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static int lfs_bd_read(lfs_t *lfs, lfs_block_t block,
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lfs_off_t off, void *buffer, lfs_size_t size) {
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uint8_t *data = buffer;
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// flush overlapping programs
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while (size > 0) {
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if (block == lfs->pcache.block && off >= lfs->pcache.off &&
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off < lfs->pcache.off + lfs->cfg->prog_size) {
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// is already in cache?
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lfs_size_t diff = lfs_min(size,
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lfs->cfg->prog_size - (off-lfs->pcache.off));
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memcpy(data, &lfs->pcache.buffer[off-lfs->pcache.off], diff);
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data += diff;
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off += diff;
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size -= diff;
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continue;
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} else if (block == lfs->rcache.block && off >= lfs->rcache.off &&
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off < lfs->rcache.off + lfs->cfg->read_size) {
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// is already in cache?
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lfs_size_t diff = lfs_min(size,
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lfs->cfg->read_size - (off-lfs->rcache.off));
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memcpy(data, &lfs->rcache.buffer[off-lfs->rcache.off], diff);
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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// write out pending programs
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int err = lfs_bd_flush(lfs);
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if (err) {
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return err;
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}
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if (off % lfs->cfg->read_size == 0 &&
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size >= lfs->cfg->read_size) {
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// bypass cache?
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lfs_size_t diff = size - (size % lfs->cfg->read_size);
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int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
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if (err) {
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return err;
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}
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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// load to cache, first condition can no longer fail
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lfs->rcache.block = block;
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lfs->rcache.off = off - (off % lfs->cfg->read_size);
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err = lfs->cfg->read(lfs->cfg, lfs->rcache.block,
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lfs->rcache.off, lfs->rcache.buffer, lfs->cfg->read_size);
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if (err) {
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return err;
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}
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}
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return 0;
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}
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static int lfs_bd_prog(lfs_t *lfs, lfs_block_t block,
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lfs_off_t off, const void *buffer, lfs_size_t size) {
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const uint8_t *data = buffer;
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if (block == lfs->rcache.block) {
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// invalidate read cache
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lfs->rcache.off = -1;
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}
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while (size > 0) {
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if (block == lfs->pcache.block && off >= lfs->pcache.off &&
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off < lfs->pcache.off + lfs->cfg->prog_size) {
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// is already in cache?
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lfs_size_t diff = lfs_min(size,
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lfs->cfg->prog_size - (off-lfs->pcache.off));
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memcpy(&lfs->pcache.buffer[off-lfs->pcache.off], data, diff);
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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// write out pending programs
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int err = lfs_bd_flush(lfs);
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if (err) {
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return err;
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}
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if (off % lfs->cfg->prog_size == 0 &&
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size >= lfs->cfg->prog_size) {
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// bypass cache?
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lfs_size_t diff = size - (size % lfs->cfg->prog_size);
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int err = lfs->cfg->prog(lfs->cfg, block, off, data, diff);
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if (err) {
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return err;
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}
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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// prepare cache, first condition can no longer fail
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lfs->pcache.block = block;
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lfs->pcache.off = off - (off % lfs->cfg->prog_size);
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}
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return 0;
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}
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static int lfs_bd_erase(lfs_t *lfs, lfs_block_t block) {
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return lfs->cfg->erase(lfs->cfg, block);
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}
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static int lfs_bd_sync(lfs_t *lfs) {
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int err = lfs_bd_flush(lfs);
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if (err) {
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return err;
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}
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return lfs->cfg->sync(lfs->cfg);
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}
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static int lfs_bd_cmp(lfs_t *lfs, lfs_block_t block,
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lfs_off_t off, lfs_size_t size, const void *buffer) {
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const uint8_t *data = buffer;
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for (lfs_off_t i = 0; i < size; i++) {
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uint8_t c;
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int err = lfs_bd_read(lfs, block, off+i, &c, 1);
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if (err) {
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return err;
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}
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if (c != data[i]) {
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return false;
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}
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}
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return true;
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}
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/// Block allocator ///
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static int lfs_alloc_lookahead(void *p, lfs_block_t block) {
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lfs_t *lfs = p;
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lfs_block_t off = (block - lfs->free.start) % lfs->cfg->block_count;
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if (off < lfs->cfg->lookahead) {
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lfs->free.lookahead[off / 32] |= 1U << (off % 32);
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}
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return 0;
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}
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static int lfs_alloc_scan(lfs_t *lfs, lfs_block_t *block) {
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lfs_block_t end = lfs->free.start + lfs->cfg->block_count;
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while (true) {
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while (lfs->free.off < lfs->cfg->lookahead) {
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lfs_block_t off = lfs->free.off;
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lfs->free.off += 1;
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if (!(lfs->free.lookahead[off / 32] & (1U << (off % 32)))) {
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// found a free block
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*block = (lfs->free.start + off) % lfs->cfg->block_count;
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return 0;
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}
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}
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// could not find block
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lfs->free.start += lfs->cfg->lookahead;
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lfs->free.off = 0;
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if (lfs_scmp(lfs->free.start, end) > 0) {
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return LFS_ERR_NOSPC;
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}
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// find mask of free blocks from tree
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memset(lfs->free.lookahead, 0, lfs->cfg->lookahead/8);
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int err = lfs_traverse(lfs, lfs_alloc_lookahead, lfs);
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if (err) {
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return err;
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}
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}
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}
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static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
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// try to scan for free block
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int err = lfs_alloc_scan(lfs, block);
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if (err != LFS_ERR_NOSPC) {
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return err;
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}
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// still can't allocate a block? check for orphans
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err = lfs_deorphan(lfs);
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if (err) {
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return err;
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}
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// scan again or die trying
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err = lfs_alloc_scan(lfs, block);
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if (err) {
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LFS_WARN("No more free space%s", "");
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return err;
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}
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return 0;
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}
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/// Metadata pair and directory operations ///
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static inline void lfs_pairswap(lfs_block_t pair[2]) {
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lfs_block_t t = pair[0];
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pair[0] = pair[1];
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pair[1] = t;
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}
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static inline bool lfs_pairisnull(const lfs_block_t pair[2]) {
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return !pair[0] || !pair[1];
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}
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static inline int lfs_paircmp(
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const lfs_block_t paira[2],
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const lfs_block_t pairb[2]) {
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return !(paira[0] == pairb[0] || paira[1] == pairb[1] ||
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paira[0] == pairb[1] || paira[1] == pairb[0]);
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}
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static int lfs_dir_alloc(lfs_t *lfs, lfs_dir_t *dir) {
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// allocate pair of dir blocks
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for (int i = 0; i < 2; i++) {
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int err = lfs_alloc(lfs, &dir->pair[i]);
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if (err) {
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return err;
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}
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}
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// we couldn't find unique blocks, we're out of space
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if (dir->pair[0] == dir->pair[1]) {
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return LFS_ERR_NOSPC;
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}
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// rather than clobbering one of the blocks we just pretend
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// the revision may be valid
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int err = lfs_bd_read(lfs, dir->pair[0], 0, &dir->d.rev, 4);
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if (err) {
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return err;
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}
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// set defaults
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dir->d.rev += 1;
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dir->d.size = sizeof(dir->d);
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dir->d.tail[0] = 0;
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dir->d.tail[1] = 0;
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dir->off = sizeof(dir->d);
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// don't write out yet, let caller take care of that
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return 0;
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}
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static int lfs_dir_fetch(lfs_t *lfs,
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lfs_dir_t *dir, const lfs_block_t pair[2]) {
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// copy out pair, otherwise may be aliasing dir
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const lfs_block_t tpair[2] = {pair[0], pair[1]};
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bool valid = false;
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// check both blocks for the most recent revision
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for (int i = 0; i < 2; i++) {
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struct lfs_disk_dir test;
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int err = lfs_bd_read(lfs, tpair[i], 0, &test, sizeof(test));
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if (err) {
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return err;
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}
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if (valid && lfs_scmp(test.rev, dir->d.rev) < 0) {
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continue;
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}
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uint32_t crc = 0xffffffff;
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crc = lfs_crc(crc, &test, sizeof(test));
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for (lfs_off_t j = sizeof(test); j < lfs->cfg->block_size; j += 4) {
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uint32_t word;
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int err = lfs_bd_read(lfs, tpair[i], j, &word, 4);
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if (err) {
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return err;
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}
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crc = lfs_crc(crc, &word, 4);
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}
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if (crc != 0) {
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continue;
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}
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valid = true;
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// setup dir in case it's valid
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dir->pair[0] = tpair[(i+0) % 2];
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dir->pair[1] = tpair[(i+1) % 2];
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dir->off = sizeof(dir->d);
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dir->d = test;
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}
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if (!valid) {
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LFS_ERROR("Corrupted dir pair at %d %d", tpair[0], tpair[1]);
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return LFS_ERR_CORRUPT;
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}
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return 0;
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}
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static int lfs_dir_commit(lfs_t *lfs, lfs_dir_t *dir,
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const lfs_entry_t *entry, const void *data) {
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dir->d.rev += 1;
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lfs_pairswap(dir->pair);
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int err = lfs_bd_erase(lfs, dir->pair[0]);
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if (err) {
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return err;
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}
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uint32_t crc = 0xffffffff;
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crc = lfs_crc(crc, &dir->d, sizeof(dir->d));
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err = lfs_bd_prog(lfs, dir->pair[0], 0, &dir->d, sizeof(dir->d));
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if (err) {
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return err;
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}
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lfs_off_t off = sizeof(dir->d);
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lfs_size_t size = 0x7fffffff & dir->d.size;
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while (off < size) {
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if (entry && off == entry->off) {
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crc = lfs_crc(crc, &entry->d, sizeof(entry->d));
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int err = lfs_bd_prog(lfs, dir->pair[0],
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off, &entry->d, sizeof(entry->d));
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if (err) {
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return err;
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}
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off += sizeof(entry->d);
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if (data) {
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crc = lfs_crc(crc, data, entry->d.len - sizeof(entry->d));
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int err = lfs_bd_prog(lfs, dir->pair[0],
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off, data, entry->d.len - sizeof(entry->d));
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if (err) {
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return err;
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}
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off += entry->d.len - sizeof(entry->d);
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}
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} else {
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uint8_t data;
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int err = lfs_bd_read(lfs, dir->pair[1], off, &data, 1);
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if (err) {
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return err;
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}
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crc = lfs_crc(crc, &data, 1);
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err = lfs_bd_prog(lfs, dir->pair[0], off, &data, 1);
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if (err) {
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return err;
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}
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off += 1;
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}
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}
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while (off < lfs->cfg->block_size-4) {
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uint8_t data = 0xff;
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crc = lfs_crc(crc, &data, 1);
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err = lfs_bd_prog(lfs, dir->pair[0], off, &data, 1);
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if (err) {
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return err;
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}
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off += 1;
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}
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err = lfs_bd_prog(lfs, dir->pair[0], lfs->cfg->block_size-4, &crc, 4);
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if (err) {
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return err;
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}
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return lfs_bd_sync(lfs);
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}
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static int lfs_dir_shift(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
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dir->d.rev += 1;
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dir->d.size -= entry->d.len;
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lfs_pairswap(dir->pair);
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int err = lfs_bd_erase(lfs, dir->pair[0]);
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if (err) {
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return err;
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}
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uint32_t crc = 0xffffffff;
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crc = lfs_crc(crc, &dir->d, sizeof(dir->d));
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err = lfs_bd_prog(lfs, dir->pair[0], 0, &dir->d, sizeof(dir->d));
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if (err) {
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return err;
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}
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lfs_off_t woff = sizeof(dir->d);
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lfs_off_t roff = sizeof(dir->d);
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lfs_size_t size = 0x7fffffff & dir->d.size;
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while (woff < size) {
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if (roff == entry->off) {
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roff += entry->d.len;
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} else {
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uint8_t data;
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int err = lfs_bd_read(lfs, dir->pair[1], roff, &data, 1);
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if (err) {
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return err;
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}
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crc = lfs_crc(crc, &data, 1);
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err = lfs_bd_prog(lfs, dir->pair[0], woff, &data, 1);
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if (err) {
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return err;
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}
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woff += 1;
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roff += 1;
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}
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}
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while (woff < lfs->cfg->block_size-4) {
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uint8_t data = 0xff;
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crc = lfs_crc(crc, &data, 1);
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err = lfs_bd_prog(lfs, dir->pair[0], woff, &data, 1);
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if (err) {
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return err;
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}
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woff += 1;
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}
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err = lfs_bd_prog(lfs, dir->pair[0], lfs->cfg->block_size-4, &crc, 4);
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if (err) {
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return err;
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}
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return lfs_bd_sync(lfs);
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}
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static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
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lfs_entry_t *entry, const void *data) {
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// check if we fit, if top bit is set we do not and move on
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while (true) {
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if (dir->d.size + entry->d.len <= lfs->cfg->block_size - 4) {
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entry->off = dir->d.size;
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dir->d.size += entry->d.len;
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return lfs_dir_commit(lfs, dir, entry, data);
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}
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// we need to allocate a new dir block
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if (!(0x80000000 & dir->d.size)) {
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lfs_dir_t newdir;
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int err = lfs_dir_alloc(lfs, &newdir);
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if (err) {
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return err;
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}
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// our allocator doesn't track blocks before being appended,
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// so even if we found some blocks, they may not be unique
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if (entry->d.type == LFS_TYPE_DIR &&
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lfs_paircmp(entry->d.u.dir, newdir.pair) == 0) {
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return LFS_ERR_NOSPC;
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}
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newdir.d.tail[0] = dir->d.tail[0];
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newdir.d.tail[1] = dir->d.tail[1];
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entry->off = newdir.d.size;
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newdir.d.size += entry->d.len;
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err = lfs_dir_commit(lfs, &newdir, entry, data);
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if (err) {
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return err;
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}
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dir->d.size |= 0x80000000;
|
|
dir->d.tail[0] = newdir.pair[0];
|
|
dir->d.tail[1] = newdir.pair[1];
|
|
return lfs_dir_commit(lfs, dir, NULL, NULL);
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
|
|
// either shift out the one entry or remove the whole dir block
|
|
if (dir->d.size == sizeof(dir->d)) {
|
|
lfs_dir_t pdir;
|
|
int err = lfs_dir_fetch(lfs, &pdir, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
while (lfs_paircmp(pdir.d.tail, dir->pair) != 0) {
|
|
int err = lfs_dir_fetch(lfs, &pdir, pdir.d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (!(pdir.d.size & 0x80000000)) {
|
|
return lfs_dir_shift(lfs, dir, entry);
|
|
} else {
|
|
pdir.d.tail[0] = dir->d.tail[0];
|
|
pdir.d.tail[1] = dir->d.tail[1];
|
|
return lfs_dir_commit(lfs, &pdir, NULL, NULL);
|
|
}
|
|
} else {
|
|
return lfs_dir_shift(lfs, dir, entry);
|
|
}
|
|
}
|
|
|
|
static int lfs_dir_next(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
|
|
while (true) {
|
|
if (dir->off + sizeof(entry->d) > (0x7fffffff & dir->d.size)) {
|
|
if (!(0x80000000 & dir->d.size)) {
|
|
entry->off = dir->off;
|
|
return LFS_ERR_NOENT;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir->off = sizeof(dir->d);
|
|
dir->pos += sizeof(dir->d);
|
|
continue;
|
|
}
|
|
|
|
int err = lfs_bd_read(lfs, dir->pair[0], dir->off,
|
|
&entry->d, sizeof(entry->d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir->off += entry->d.len;
|
|
dir->pos += entry->d.len;
|
|
if ((0xff & entry->d.type) == LFS_TYPE_REG ||
|
|
(0xff & entry->d.type) == LFS_TYPE_DIR) {
|
|
entry->off = dir->off - entry->d.len;
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
|
|
lfs_entry_t *entry, const char **path) {
|
|
const char *pathname = *path;
|
|
size_t pathlen;
|
|
|
|
while (true) {
|
|
nextname:
|
|
// skip slashes
|
|
pathname += strspn(pathname, "/");
|
|
pathlen = strcspn(pathname, "/");
|
|
|
|
// skip '.' and root '..'
|
|
if ((pathlen == 1 && memcmp(pathname, ".", 1) == 0) ||
|
|
(pathlen == 2 && memcmp(pathname, "..", 2) == 0)) {
|
|
pathname += pathlen;
|
|
goto nextname;
|
|
}
|
|
|
|
// skip if matched by '..' in name
|
|
const char *suffix = pathname + pathlen;
|
|
size_t sufflen;
|
|
int depth = 1;
|
|
while (true) {
|
|
suffix += strspn(suffix, "/");
|
|
sufflen = strcspn(suffix, "/");
|
|
if (sufflen == 0) {
|
|
break;
|
|
}
|
|
|
|
if (sufflen == 2 && memcmp(suffix, "..", 2) == 0) {
|
|
depth -= 1;
|
|
if (depth == 0) {
|
|
pathname = suffix + sufflen;
|
|
goto nextname;
|
|
}
|
|
} else {
|
|
depth += 1;
|
|
}
|
|
|
|
suffix += sufflen;
|
|
}
|
|
|
|
// find path
|
|
while (true) {
|
|
int err = lfs_dir_next(lfs, dir, entry);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (entry->d.len - sizeof(entry->d) != pathlen) {
|
|
continue;
|
|
}
|
|
|
|
int ret = lfs_bd_cmp(lfs, dir->pair[0],
|
|
entry->off + sizeof(entry->d), pathlen, pathname);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
// Found match
|
|
if (ret == true) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
pathname += pathlen;
|
|
pathname += strspn(pathname, "/");
|
|
if (pathname[0] == '\0') {
|
|
return 0;
|
|
}
|
|
|
|
// continue on if we hit a directory
|
|
if (entry->d.type != LFS_TYPE_DIR) {
|
|
return LFS_ERR_NOTDIR;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, entry->d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
*path = pathname;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Top level directory operations ///
|
|
int lfs_mkdir(lfs_t *lfs, const char *path) {
|
|
// fetch parent directory
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err != LFS_ERR_NOENT) {
|
|
return err ? err : LFS_ERR_EXISTS;
|
|
}
|
|
|
|
// Build up new directory
|
|
lfs_dir_t dir;
|
|
err = lfs_dir_alloc(lfs, &dir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
dir.d.tail[0] = cwd.d.tail[0];
|
|
dir.d.tail[1] = cwd.d.tail[1];
|
|
|
|
err = lfs_dir_commit(lfs, &dir, NULL, NULL);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
entry.d.type = LFS_TYPE_DIR;
|
|
entry.d.len = sizeof(entry.d) + strlen(path);
|
|
entry.d.u.dir[0] = dir.pair[0];
|
|
entry.d.u.dir[1] = dir.pair[1];
|
|
|
|
cwd.d.tail[0] = dir.pair[0];
|
|
cwd.d.tail[1] = dir.pair[1];
|
|
|
|
return lfs_dir_append(lfs, &cwd, &entry, path);
|
|
}
|
|
|
|
int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
|
|
dir->pair[0] = lfs->root[0];
|
|
dir->pair[1] = lfs->root[1];
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->pair);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (strspn(path, "/.") == strlen(path)) {
|
|
// can only be something like '/././../.'
|
|
dir->head[0] = dir->pair[0];
|
|
dir->head[1] = dir->pair[1];
|
|
dir->pos = sizeof(dir->d) - 2;
|
|
dir->off = sizeof(dir->d);
|
|
return 0;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, dir, &entry, &path);
|
|
if (err) {
|
|
return err;
|
|
} else if (entry.d.type != LFS_TYPE_DIR) {
|
|
return LFS_ERR_NOTDIR;
|
|
}
|
|
|
|
err = lfs_dir_fetch(lfs, dir, entry.d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// setup head dir
|
|
// special offset for '.' and '..'
|
|
dir->head[0] = dir->pair[0];
|
|
dir->head[1] = dir->pair[1];
|
|
dir->pos = sizeof(dir->d) - 2;
|
|
dir->off = sizeof(dir->d);
|
|
return 0;
|
|
}
|
|
|
|
int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
|
|
// Do nothing, dir is always synchronized
|
|
return 0;
|
|
}
|
|
|
|
int lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info) {
|
|
memset(info, 0, sizeof(*info));
|
|
|
|
// special offset for '.' and '..'
|
|
if (dir->pos == sizeof(dir->d) - 2) {
|
|
info->type = LFS_TYPE_DIR;
|
|
strcpy(info->name, ".");
|
|
dir->pos += 1;
|
|
return 1;
|
|
} else if (dir->pos == sizeof(dir->d) - 1) {
|
|
info->type = LFS_TYPE_DIR;
|
|
strcpy(info->name, "..");
|
|
dir->pos += 1;
|
|
return 1;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
int err = lfs_dir_next(lfs, dir, &entry);
|
|
if (err) {
|
|
return (err == LFS_ERR_NOENT) ? 0 : err;
|
|
}
|
|
|
|
info->type = entry.d.type & 0xff;
|
|
if (info->type == LFS_TYPE_REG) {
|
|
info->size = entry.d.u.file.size;
|
|
}
|
|
|
|
err = lfs_bd_read(lfs, dir->pair[0], entry.off + sizeof(entry.d),
|
|
info->name, entry.d.len - sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off) {
|
|
// simply walk from head dir
|
|
int err = lfs_dir_rewind(lfs, dir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
dir->pos = off;
|
|
|
|
while (off > (0x7fffffff & dir->d.size)) {
|
|
off -= 0x7fffffff & dir->d.size;
|
|
if (!(0x80000000 & dir->d.size)) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
dir->off = off;
|
|
return 0;
|
|
}
|
|
|
|
lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir) {
|
|
return dir->pos;
|
|
}
|
|
|
|
int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir) {
|
|
// reload the head dir
|
|
int err = lfs_dir_fetch(lfs, dir, dir->head);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir->pair[0] = dir->head[0];
|
|
dir->pair[1] = dir->head[1];
|
|
dir->pos = sizeof(dir->d) - 2;
|
|
dir->off = sizeof(dir->d);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Index list operations ///
|
|
static int lfs_index(lfs_t *lfs, lfs_off_t *off) {
|
|
lfs_off_t i = 0;
|
|
|
|
while (*off >= lfs->cfg->block_size) {
|
|
i += 1;
|
|
*off -= lfs->cfg->block_size;
|
|
*off += 4*lfs_min(lfs_ctz(i)+1, lfs->words-1);
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
static int lfs_index_find(lfs_t *lfs, lfs_block_t head, lfs_size_t size,
|
|
lfs_size_t pos, lfs_block_t *block, lfs_off_t *off) {
|
|
if (size == 0) {
|
|
*block = 0;
|
|
*off = 0;
|
|
return 0;
|
|
}
|
|
|
|
lfs_off_t current = lfs_index(lfs, &(lfs_off_t){size-1});
|
|
lfs_off_t target = lfs_index(lfs, &pos);
|
|
|
|
while (current > target) {
|
|
lfs_size_t skip = lfs_min(
|
|
lfs_npw2(current-target+1) - 1,
|
|
lfs_min(lfs_ctz(current)+1, lfs->words-1) - 1);
|
|
|
|
int err = lfs_bd_read(lfs, head, 4*skip, &head, 4);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
current -= 1 << skip;
|
|
}
|
|
|
|
*block = head;
|
|
*off = pos;
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_index_extend(lfs_t *lfs,
|
|
lfs_block_t head, lfs_size_t size,
|
|
lfs_off_t *block, lfs_block_t *off) {
|
|
// go ahead and grab a block
|
|
int err = lfs_alloc(lfs, block);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_bd_erase(lfs, *block);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (size == 0) {
|
|
*off = 0;
|
|
return 0;
|
|
}
|
|
|
|
size -= 1;
|
|
lfs_off_t index = lfs_index(lfs, &size);
|
|
size += 1;
|
|
|
|
// just copy out the last block if it is incomplete
|
|
if (size != lfs->cfg->block_size) {
|
|
for (lfs_off_t i = 0; i < size; i++) {
|
|
uint8_t data;
|
|
int err = lfs_bd_read(lfs, head, i, &data, 1);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_bd_prog(lfs, *block, i, &data, 1);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
*off = size;
|
|
return 0;
|
|
}
|
|
|
|
// append block
|
|
index += 1;
|
|
lfs_size_t skips = lfs_min(lfs_ctz(index)+1, lfs->words-1);
|
|
|
|
for (lfs_off_t i = 0; i < skips; i++) {
|
|
int err = lfs_bd_prog(lfs, *block, 4*i, &head, 4);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (i != skips-1) {
|
|
err = lfs_bd_read(lfs, head, 4*i, &head, 4);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
*off = 4*skips;
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_index_traverse(lfs_t *lfs,
|
|
lfs_block_t head, lfs_size_t size,
|
|
int (*cb)(void*, lfs_block_t), void *data) {
|
|
if (size == 0) {
|
|
return 0;
|
|
}
|
|
|
|
lfs_off_t index = lfs_index(lfs, &(lfs_off_t){size-1});
|
|
|
|
while (true) {
|
|
int err = cb(data, head);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (index == 0) {
|
|
return 0;
|
|
}
|
|
|
|
err = lfs_bd_read(lfs, head, 0, &head, 4);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
index -= 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Top level file operations ///
|
|
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
|
|
const char *path, int flags) {
|
|
// Allocate entry for file if it doesn't exist
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err && err != LFS_ERR_NOENT) {
|
|
return err;
|
|
}
|
|
|
|
if (err == LFS_ERR_NOENT) {
|
|
if (!(flags & LFS_O_CREAT)) {
|
|
return LFS_ERR_NOENT;
|
|
}
|
|
|
|
// create entry to remember name
|
|
entry.d.type = LFS_TYPE_REG;
|
|
entry.d.len = sizeof(entry.d) + strlen(path);
|
|
entry.d.u.file.head = 0;
|
|
entry.d.u.file.size = 0;
|
|
err = lfs_dir_append(lfs, &cwd, &entry, path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
} else if (entry.d.type == LFS_TYPE_DIR) {
|
|
return LFS_ERR_ISDIR;
|
|
} else if (flags & LFS_O_EXCL) {
|
|
return LFS_ERR_EXISTS;
|
|
}
|
|
|
|
// setup file struct
|
|
file->pair[0] = cwd.pair[0];
|
|
file->pair[1] = cwd.pair[1];
|
|
file->off = entry.off;
|
|
file->head = entry.d.u.file.head;
|
|
file->size = entry.d.u.file.size;
|
|
file->flags = flags;
|
|
file->pos = 0;
|
|
file->wblock = 0;
|
|
file->rblock = 0;
|
|
|
|
if (flags & LFS_O_TRUNC) {
|
|
file->head = 0;
|
|
file->size = 0;
|
|
}
|
|
|
|
// add to list of files
|
|
file->next = lfs->files;
|
|
lfs->files = file;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
|
|
int err = lfs_file_sync(lfs, file);
|
|
|
|
// remove from list of files
|
|
for (lfs_file_t **p = &lfs->files; *p; p = &(*p)->next) {
|
|
if (*p == file) {
|
|
*p = file->next;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
|
|
if (file->rblock) {
|
|
// just drop read block
|
|
file->rblock = 0;
|
|
}
|
|
|
|
if (file->wblock) {
|
|
lfs_off_t pos = file->pos;
|
|
|
|
// copy over anything after current branch
|
|
lfs_file_t orig = {
|
|
.head = file->head,
|
|
.size = file->size,
|
|
.flags = LFS_O_RDONLY,
|
|
.pos = file->pos,
|
|
.rblock = 0,
|
|
};
|
|
|
|
while (file->pos < file->size) {
|
|
uint8_t data;
|
|
lfs_ssize_t res = lfs_file_read(lfs, &orig, &data, 1);
|
|
if (res < 0) {
|
|
return res;
|
|
}
|
|
|
|
res = lfs_file_write(lfs, file, &data, 1);
|
|
if (res < 0) {
|
|
return res;
|
|
}
|
|
}
|
|
|
|
// actual file updates
|
|
file->head = file->wblock;
|
|
file->size = file->pos;
|
|
file->wblock = 0;
|
|
file->flags |= LFS_O_DIRTY;
|
|
|
|
file->pos = pos;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
|
|
int err = lfs_file_flush(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (file->flags & LFS_O_DIRTY) {
|
|
// update dir entry
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, file->pair);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry = {.off = file->off};
|
|
err = lfs_bd_read(lfs, cwd.pair[0], entry.off,
|
|
&entry.d, sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (entry.d.type != LFS_TYPE_REG) {
|
|
// sanity check valid entry
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
entry.d.u.file.head = file->head;
|
|
entry.d.u.file.size = file->size;
|
|
|
|
err = lfs_dir_commit(lfs, &cwd, &entry, NULL);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
file->flags &= ~LFS_O_DIRTY;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
|
|
void *buffer, lfs_size_t size) {
|
|
uint8_t *data = buffer;
|
|
lfs_size_t nsize = size;
|
|
|
|
if ((file->flags & 3) == LFS_O_WRONLY) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
if (file->wblock) {
|
|
// flush out any writes
|
|
int err = lfs_file_flush(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
size = lfs_min(size, file->size - file->pos);
|
|
nsize = size;
|
|
|
|
while (nsize > 0) {
|
|
// check if we need a new block
|
|
if (!file->rblock || file->roff == lfs->cfg->block_size) {
|
|
int err = lfs_index_find(lfs, file->head, file->size,
|
|
file->pos, &file->rblock, &file->roff);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// read as much as we can in current block
|
|
lfs_size_t diff = lfs_min(nsize, lfs->cfg->block_size - file->roff);
|
|
int err = lfs_bd_read(lfs, file->rblock, file->roff, data, diff);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
file->pos += diff;
|
|
file->roff += diff;
|
|
data += diff;
|
|
nsize -= diff;
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
|
|
const void *buffer, lfs_size_t size) {
|
|
const uint8_t *data = buffer;
|
|
lfs_size_t nsize = size;
|
|
|
|
if ((file->flags & 3) == LFS_O_RDONLY) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
if (file->rblock) {
|
|
// drop any reads
|
|
int err = lfs_file_flush(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if ((file->flags & LFS_O_APPEND) && file->pos < file->size) {
|
|
file->pos = file->size;
|
|
}
|
|
|
|
while (nsize > 0) {
|
|
// check if we need a new block
|
|
if (!file->wblock || file->woff == lfs->cfg->block_size) {
|
|
if (!file->wblock) {
|
|
// find out which block we're extending from
|
|
int err = lfs_index_find(lfs, file->head, file->size,
|
|
file->pos, &file->wblock, &file->woff);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// extend file with new blocks
|
|
int err = lfs_index_extend(lfs, file->wblock, file->pos,
|
|
&file->wblock, &file->woff);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// program as much as we can in current block
|
|
lfs_size_t diff = lfs_min(nsize, lfs->cfg->block_size - file->woff);
|
|
int err = lfs_bd_prog(lfs, file->wblock, file->woff, data, diff);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
file->pos += diff;
|
|
file->woff += diff;
|
|
data += diff;
|
|
nsize -= diff;
|
|
}
|
|
|
|
if (file->flags & LFS_O_SYNC) {
|
|
int err = lfs_file_sync(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
|
|
lfs_soff_t off, int whence) {
|
|
// write out everything beforehand, may be noop if rdonly
|
|
int err = lfs_file_flush(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// update pos
|
|
lfs_off_t pos = file->pos;
|
|
|
|
if (whence == LFS_SEEK_SET) {
|
|
file->pos = off;
|
|
} else if (whence == LFS_SEEK_CUR) {
|
|
file->pos = file->pos + off;
|
|
} else if (whence == LFS_SEEK_END) {
|
|
file->pos = file->size + off;
|
|
}
|
|
|
|
return pos;
|
|
}
|
|
|
|
lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file) {
|
|
return file->pos;
|
|
}
|
|
|
|
int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file) {
|
|
lfs_soff_t res = lfs_file_seek(lfs, file, 0, LFS_SEEK_SET);
|
|
if (res < 0) {
|
|
return res;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file) {
|
|
return lfs_max(file->pos, file->size);
|
|
}
|
|
|
|
|
|
/// General fs oprations ///
|
|
int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
memset(info, 0, sizeof(*info));
|
|
info->type = entry.d.type & 0xff;
|
|
if (info->type == LFS_TYPE_REG) {
|
|
info->size = entry.d.u.file.size;
|
|
}
|
|
|
|
err = lfs_bd_read(lfs, cwd.pair[0], entry.off + sizeof(entry.d),
|
|
info->name, entry.d.len - sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_remove(lfs_t *lfs, const char *path) {
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_dir_t dir;
|
|
if (entry.d.type == LFS_TYPE_DIR) {
|
|
// must be empty before removal, checking size
|
|
// without masking top bit checks for any case where
|
|
// dir is not empty
|
|
int err = lfs_dir_fetch(lfs, &dir, entry.d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
} else if (dir.d.size != sizeof(dir.d)) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
}
|
|
|
|
// remove the entry
|
|
err = lfs_dir_remove(lfs, &cwd, &entry);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// if we were a directory, just run a deorphan step, this should
|
|
// collect us, although is expensive
|
|
if (entry.d.type == LFS_TYPE_DIR) {
|
|
int err = lfs_deorphan(lfs);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
|
|
// find old entry
|
|
lfs_dir_t oldcwd;
|
|
int err = lfs_dir_fetch(lfs, &oldcwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t oldentry;
|
|
err = lfs_dir_find(lfs, &oldcwd, &oldentry, &oldpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// allocate new entry
|
|
lfs_dir_t newcwd;
|
|
err = lfs_dir_fetch(lfs, &newcwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t preventry;
|
|
err = lfs_dir_find(lfs, &newcwd, &preventry, &newpath);
|
|
if (err && err != LFS_ERR_NOENT) {
|
|
return err;
|
|
}
|
|
bool prevexists = (err != LFS_ERR_NOENT);
|
|
|
|
// must have same type
|
|
if (prevexists && preventry.d.type != oldentry.d.type) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
lfs_dir_t dir;
|
|
if (prevexists && preventry.d.type == LFS_TYPE_DIR) {
|
|
// must be empty before removal, checking size
|
|
// without masking top bit checks for any case where
|
|
// dir is not empty
|
|
int err = lfs_dir_fetch(lfs, &dir, preventry.d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
} else if (dir.d.size != sizeof(dir.d)) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
}
|
|
|
|
// move to new location
|
|
lfs_entry_t newentry = preventry;
|
|
newentry.d = oldentry.d;
|
|
newentry.d.len = sizeof(newentry.d) + strlen(newpath);
|
|
|
|
if (prevexists) {
|
|
int err = lfs_dir_commit(lfs, &newcwd, &newentry, newpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
} else {
|
|
int err = lfs_dir_append(lfs, &newcwd, &newentry, newpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// fetch again in case newcwd == oldcwd
|
|
err = lfs_dir_fetch(lfs, &oldcwd, oldcwd.pair);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_dir_find(lfs, &oldcwd, &oldentry, &oldpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// remove from old location
|
|
err = lfs_dir_remove(lfs, &oldcwd, &oldentry);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// if we were a directory, just run a deorphan step, this should
|
|
// collect us, although is expensive
|
|
if (prevexists && preventry.d.type == LFS_TYPE_DIR) {
|
|
int err = lfs_deorphan(lfs);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Filesystem operations ///
|
|
static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
|
|
lfs->cfg = cfg;
|
|
lfs->words = lfs->cfg->block_size / sizeof(uint32_t);
|
|
|
|
// setup read cache
|
|
lfs->rcache.off = -1;
|
|
if (lfs->cfg->read_buffer) {
|
|
lfs->rcache.buffer = lfs->cfg->read_buffer;
|
|
} else {
|
|
lfs->rcache.buffer = malloc(lfs->cfg->read_size);
|
|
if (!lfs->rcache.buffer) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
}
|
|
|
|
// setup program cache
|
|
lfs->pcache.off = -1;
|
|
if (lfs->cfg->prog_buffer) {
|
|
lfs->pcache.buffer = lfs->cfg->prog_buffer;
|
|
} else {
|
|
lfs->pcache.buffer = malloc(lfs->cfg->prog_size);
|
|
if (!lfs->pcache.buffer) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
}
|
|
|
|
// setup lookahead
|
|
if (lfs->cfg->lookahead_buffer) {
|
|
lfs->free.lookahead = lfs->cfg->lookahead_buffer;
|
|
} else {
|
|
lfs->free.lookahead = malloc(lfs->cfg->lookahead/8);
|
|
if (!lfs->free.lookahead) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
}
|
|
|
|
// setup files as an empty list
|
|
lfs->files = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_deinit(lfs_t *lfs) {
|
|
// Free allocated memory
|
|
if (!lfs->cfg->read_buffer) {
|
|
free(lfs->rcache.buffer);
|
|
}
|
|
|
|
if (!lfs->cfg->prog_buffer) {
|
|
free(lfs->pcache.buffer);
|
|
}
|
|
|
|
if (!lfs->cfg->lookahead_buffer) {
|
|
free(lfs->free.lookahead);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
|
|
int err = lfs_init(lfs, cfg);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// Create free lookahead
|
|
memset(lfs->free.lookahead, 0, lfs->cfg->lookahead/8);
|
|
lfs->free.start = 0;
|
|
lfs->free.off = 0;
|
|
|
|
// Create superblock dir
|
|
lfs_dir_t superdir;
|
|
err = lfs_dir_alloc(lfs, &superdir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// Write root directory
|
|
lfs_dir_t root;
|
|
err = lfs_dir_alloc(lfs, &root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_dir_commit(lfs, &root, NULL, NULL);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs->root[0] = root.pair[0];
|
|
lfs->root[1] = root.pair[1];
|
|
|
|
// Write superblocks
|
|
lfs_superblock_t superblock = {
|
|
.off = sizeof(superdir.d),
|
|
.d.type = LFS_TYPE_SUPERBLOCK,
|
|
.d.len = sizeof(superblock.d),
|
|
.d.version = 0x00000001,
|
|
.d.magic = {"littlefs"},
|
|
.d.block_size = lfs->cfg->block_size,
|
|
.d.block_count = lfs->cfg->block_count,
|
|
.d.root = {lfs->root[0], lfs->root[1]},
|
|
};
|
|
superdir.d.tail[0] = root.pair[0];
|
|
superdir.d.tail[1] = root.pair[1];
|
|
superdir.d.size += sizeof(superdir.d);
|
|
|
|
for (int i = 0; i < 2; i++) {
|
|
// Write both pairs for extra safety, do some finagling to pretend
|
|
// the superblock is an entry
|
|
int err = lfs_dir_commit(lfs, &superdir,
|
|
(const lfs_entry_t*)&superblock,
|
|
(const struct lfs_disk_entry*)&superblock.d + 1);
|
|
if (err) {
|
|
LFS_ERROR("Failed to write superblock at %d", superdir.pair[0]);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// sanity check that fetch works
|
|
err = lfs_dir_fetch(lfs, &superdir, (const lfs_block_t[2]){0, 1});
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
return lfs_deinit(lfs);
|
|
}
|
|
|
|
int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
|
|
int err = lfs_init(lfs, cfg);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// setup free lookahead
|
|
lfs->free.start = -lfs->cfg->lookahead;
|
|
lfs->free.off = lfs->cfg->lookahead;
|
|
|
|
// load superblock
|
|
lfs_dir_t dir;
|
|
lfs_superblock_t superblock;
|
|
err = lfs_dir_fetch(lfs, &dir, (const lfs_block_t[2]){0, 1});
|
|
if (!err) {
|
|
err = lfs_bd_read(lfs, dir.pair[0],
|
|
sizeof(dir.d), &superblock.d, sizeof(superblock.d));
|
|
|
|
lfs->root[0] = superblock.d.root[0];
|
|
lfs->root[1] = superblock.d.root[1];
|
|
}
|
|
|
|
if (err == LFS_ERR_CORRUPT ||
|
|
memcmp(superblock.d.magic, "littlefs", 8) != 0) {
|
|
LFS_ERROR("Invalid superblock at %d %d", dir.pair[0], dir.pair[1]);
|
|
return LFS_ERR_CORRUPT;
|
|
}
|
|
|
|
if (superblock.d.version > 0x0000ffff) {
|
|
LFS_ERROR("Invalid version %d.%d\n",
|
|
0xffff & (superblock.d.version >> 16),
|
|
0xffff & (superblock.d.version >> 0));
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
int lfs_unmount(lfs_t *lfs) {
|
|
return lfs_deinit(lfs);
|
|
}
|
|
|
|
|
|
/// Littlefs specific operations ///
|
|
int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data) {
|
|
// iterate over metadata pairs
|
|
lfs_dir_t dir;
|
|
lfs_entry_t entry;
|
|
lfs_block_t cwd[2] = {0, 1};
|
|
|
|
while (true) {
|
|
for (int i = 0; i < 2; i++) {
|
|
int err = cb(data, cwd[i]);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, &dir, cwd);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// iterate over contents
|
|
while ((0x7fffffff & dir.d.size) >= dir.off + sizeof(entry.d)) {
|
|
int err = lfs_bd_read(lfs, dir.pair[0], dir.off,
|
|
&entry.d, sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir.off += entry.d.len;
|
|
if ((0xf & entry.d.type) == LFS_TYPE_REG) {
|
|
int err = lfs_index_traverse(lfs,
|
|
entry.d.u.file.head, entry.d.u.file.size, cb, data);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
cwd[0] = dir.d.tail[0];
|
|
cwd[1] = dir.d.tail[1];
|
|
|
|
if (lfs_pairisnull(cwd)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// iterate over any open files
|
|
for (lfs_file_t *f = lfs->files; f; f = f->next) {
|
|
if (f->flags & LFS_O_DIRTY) {
|
|
int err = lfs_index_traverse(lfs, f->head, f->size, cb, data);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (f->wblock) {
|
|
int err = lfs_index_traverse(lfs, f->wblock, f->pos, cb, data);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_parent(lfs_t *lfs, const lfs_block_t dir[2]) {
|
|
// iterate over all directory directory entries
|
|
lfs_dir_t parent = {
|
|
.d.tail[0] = lfs->root[0],
|
|
.d.tail[1] = lfs->root[1],
|
|
};
|
|
|
|
while (true) {
|
|
lfs_entry_t entry;
|
|
int err = lfs_dir_fetch(lfs, &parent, parent.d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
while (true) {
|
|
int err = lfs_dir_next(lfs, &parent, &entry);
|
|
if (err && err != LFS_ERR_NOENT) {
|
|
return err;
|
|
}
|
|
|
|
if (err == LFS_ERR_NOENT) {
|
|
break;
|
|
}
|
|
|
|
if ((0xf & entry.d.type) == LFS_TYPE_DIR &&
|
|
lfs_paircmp(entry.d.u.dir, dir) == 0) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
if (lfs_pairisnull(parent.d.tail)) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
int lfs_deorphan(lfs_t *lfs) {
|
|
// iterate over all directories
|
|
lfs_dir_t pdir;
|
|
lfs_dir_t cdir;
|
|
|
|
// skip root
|
|
int err = lfs_dir_fetch(lfs, &pdir, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
while (!lfs_pairisnull(pdir.d.tail)) {
|
|
int err = lfs_dir_fetch(lfs, &cdir, pdir.d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// only check head blocks
|
|
if (!(0x80000000 & pdir.d.size)) {
|
|
// check if we have a parent
|
|
int parent = lfs_parent(lfs, pdir.d.tail);
|
|
if (parent < 0) {
|
|
return parent;
|
|
}
|
|
|
|
if (!parent) {
|
|
// we are an orphan
|
|
LFS_DEBUG("Orphan %d %d", pdir.d.tail[0], pdir.d.tail[1]);
|
|
|
|
pdir.d.tail[0] = cdir.d.tail[0];
|
|
pdir.d.tail[1] = cdir.d.tail[1];
|
|
|
|
err = lfs_dir_commit(lfs, &pdir, NULL, NULL);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
memcpy(&pdir, &cdir, sizeof(pdir));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|